Graphic overlay assembly

ABSTRACT

GRAPHIC OVERLAY ASSEMBLY FOR FACILITATING COMPRISES OF INFORMATION AND FEATURING ONE OR MORE UNITARY SHEETS OF FILM-LIKE, TOUGH, FLEXIBLE TRANSPARENT MATERIAL, SUCH AS POLYETHYLENE TEREPHTHALATE, EACH DIVIDED BY A TRANSVERSE HINGE LINE INTO A SMALLER HALF AND A LARGER HALF. THE FREE EDGE OF THE LARGER HALF FACILITATES BINDING WITH OTHER SHEET MATERIAL, THE SMALLER HALF BEING IMPRINTED WITH INTELLIGENCE AND THE LARGER HALF BEING OPAQUED WITH OR WITHOUT INTELLIGENCE FOR COMPARISON WITH THE INTELLIGENCE ON THE SMALLER HALF WHEN THE LATTER IS FOLDED TO ITS   STORED POSITION. THE BINDER FOR THE OVERLAY ASSEMBLIES PREFERABLY INCLUDES A FOLD-OUT COVER IMPRINTED WITH A GRID OR OTHER SUITABLE REFERENCE GUIDE POSITIONED TO UNDERLIE AND REGISTER WITH THE INTELLIGENCE ON THE UNFOLDED SMALLER HALF OF ONE OR MORE UNFOLDED TRANSPARENCIES. A FEATURE OF THE INVENTION IS THE USE OF FILM-LIKE TRANSPARENT MATERIAL SUITABLY PROCESSED FOR REINFORCING THE FILM ADJACENT THE HINGE LINE BY ONE OF SEVERAL TECHNIQUES.

Feb. 23, 1971 s. H. GOTTLIEB GRAPHIC OVERLAY ASSEMBLY Filed Ju1y"l5.1969 3 Sheets-Sheet 1 I m 3 A W v WA 0 w INVENTOR. GERALD H. GOTTLJEB"Feb. Z3, 1971 s. H. GOTTLIEB 3,555,462

GRAPHIC OVERLAY ASSEMBLY Filed July 15, 1969 3 Sheets-Sheet z NVENTOR.GERALD' H. GOTTUEB 'I'TORNEY Feb. 23, 1971 G. H. GOTTLIEB GRAPHICOVERLAY ASSEMBLY 3 Sheets-Sheet 3 Filed July 15, 1969 &

I INVENTOR United States Patent Int. Cl. B42d N00 US. Cl. 281-3 25Claims ABSTRACT OF THE DISCLOSURE Graphic overlay assembly forfacilitating comparison of information and featuring one or more unitarysheets of film-like, tough, flexible transparent material, such aspolyethylene terephthalate, each divided by a transverse hinge line intoa smaller half and a larger half. The free edge of the larger halffacilitates binding with other sheet material, the smaller half beingimprinted with intelligence and the larger half being opaqued with orwithout intelligence for comparison with the intelligence on the smallerhalf when the latter is folded to its stored position. The binder forthe overlay assemblies preferably includes a fold-out cover imprintedwith a grid or other suitable reference guide positioned to underlie andregister with the intelligence on the unfolded smaller half of one ormore unfolded transparencies. A feature of the invention is the use offilm-like transparent material suitably processed for reinforcing thefilm adjacent the hinge line by one of several techniques.

This invention is a continuation-in-part of my copending application forUnited States Letters Patent, Ser. No. 496,922. filed Oct. 18, 1965entitled Graphic Display Device and subsequently abandoned.

This invention relates to graphic display devices and more particularlyto an improved unitary folding binder device for supporting a pluralityof folding transparencies each containing intelligence and so arrangedthat the intelligence on any two or more transparencies selected atrandom can be easily and quickly brought into true registration forconvenience While comparing and studying the information thereon.

There are a great variety of situations where it is desirable toevaluate information present on any two or more sheets. These needs areso numerous and so Widely different that it is not practical to do morethan mention typical examples. For example, economists have frequentneed for comparing charts and graphs, the same is true for teachers whowish to evaluate assorted information in any particular field; engineersoften wish to compare data and performance characteristics of similarcomponents under differing conditions; the same is true of manufacturerswho have need for studying and evaluating production rates, inventoryrequirements and other data. Other fields include text books, referencebooks, encyclopedias and books generally.

The present invention, in one preferred embodiment, utilizes three coverplaques hinged together along the opposite lateral edges of a centralmember. One of these hinge areas includes looseleaf binder means of anysuitable character in which are mounted any desired number of unitarysheets of flexible transparent material. In other applications of theinvention, the transparent assemblies may be bound together with othersheet material in con ventional manner well known to the book bindingart. Each sheet is formed in two parts, the outer part being hinged tothe inner part parallelto the binder device and being embossed, printedor otherwise provided With suitable intelligence. The size of the foldedsheets corresponds generally with the surface area of the cen- 3,565,462Patented Feb. 23, 1971 tral cover section in order that sheets notneeded for a particular comparison can be folded over against thecentral section while those selected for use are unfolded andsuperimposed upon one another for comparative analysis. Appropriatemeans are preferably provided for holding each of the unfoldedtransparencies in predetermined registry With one another and withreference guide means such as a grid fixed to the inside of the coverleaf. In this manner any number of transparencies can be compared whilethose in use remain folded and lying against the center portion of thedevice cover.

Additional features of the present invention include several highlyeffective modes of making the individual sheets from one-piecetransparent flexible material each provided with a hinge dividing thepage into two halves of different size. Desirably the larger half ofeach transparency is suitably opaqued and imprinted with a grid or otherstandard background reference material useful in the expeditiousinterpretation of the graphical information on the transparent outerhalf of the sheet when the information contained on only a singletransparency is of interest. Also, the binder means holding the sheetdetachably assembled is highly advantageous and permits different setsof either related information to be substituted and compared readily.

It is found that exceedingly tough and durable transparent films havinga thickness of as small as one and two mils are highly satisfactory,particularly when processed in accordance with the principles of thisinvention to stiffen them along the hinging area in a manner assuringrepeated hinging along the same hinge axis. This stiffening can beaccomplished in several different ways in cluding laminating thetransparency to another sheet slit coincident with the desired hingeaxis and providing a pair of edges in abutment when the transparency isunfoldedfrom a position wherein its unslit halves lie against oneanother. The stiffening layer may comprise either a transparent or anon-transparent sheet. In the former case, the larger half of thelaminated assembly may be opaqued with a pigmented layer or by othermeans. If a transparent sheet is employed to stiffen the hinge areas, itis preferably coextensive in size with the main transparency but neednot be laminated to the transparent intelligence-bearing area of thesmaller outer half of the overlay assembly. stiffening of thetransparency may also be accomplished using a coating applied along atleast strip areas of the transparency closely spaced to either side ofthe hinge axis, as well as by a combination of any two of the men tionedstiffening techniques.

Accordingly it is a primary object of the present lnvention to providean improved device for facilitatingcomparison of information on any of aplurality of similar sheets each provided with different intelligence.

Another object of the invention is the provision of a graphical displaydevice designed for compact foldmg when not in use and containing aplurality of sheets of transparent material each provided withintelligence thereon and so arranged that any of a plurality of sheetsselected at random can be brought quickly into superlmposed registrywhile comparing information on these sheets.

Another object of the invention is the provision of a graphical displaydevice having a cover formed in three principal parts hingedlyinterconnected and including ring or other binder means along one hingeadapted to hold a plurality of foldable sheets of transparent materialeach provided with intelligence thereon and including means for bringingselected sheets of information into surface contact while theinformation thereon is being evaluated.

Another object of the invention is the provision of a plurality ofgraphical display assemblies each comprising a one-piece sheet oftransparent material hinged to divide the same into halves of unequalareas each carrying intelligence and including a reference guide for usein interpreting this intelligence when the sheets are in their normalfolded conditions, the similar assemblies being bound together along oneedge and so arranged that more than one sheet can be unfolded andsuperimposed for comparative study.

Another object of the invention is the provision of a folding overlayassembly having a main body formed by a single sheet of transparentfilm-like resinous material folded transversely thereof along a hingeline offset to one side of the transverse center and stiffened at leastalong one edge of the hinge line to resist hinging except along thehinge axis and to counteract the memory properties of the hinge area.

Another object of the invention is the provision of a folding overlaycomprising a single body sheet of transparent film folded along a hingeline offset from its transverse center to form halves of unequal sizeand stiffened by an adherent layer covering said larger half and aportion of said smaller half except for a narrow gap coinciding with theaxis of the hinge line, and said stiffening layer preferably beingopaque.

Another object of the invention is the provision of a folding overlayassembly comprising a pair of transparent film-like sheets laminated toone another and including a transverse integral hinge dividing saidassembly into a large and a smaller half and formed by a portion of oneof said sheets coinciding with a slit extending through the other ofsaid sheets with the slit edges abutting one another when said halvesare unfolded to lie in a common plane and discouraging backfolding.

These and other more specific objects will appear upon reading thefollowing specification and claims and upon considering in connectiontherewith the attached drawings to which they relate.

Referring now to the drawings in which a preferred embodiment of theinvention is illustrated.

FIG. 1 is a generally perspective view of the graphical display deviceaccording to a preferred embodiment showing the device opened and readyfor use;

FIG. 2 is an end elevational view of the device in open position andshowing some of the sheets in lifted position;

FIG. 3 is a plan view of one of the information sheets in open positionas viewed from the top surface thereof;

FIGS. 4, and 6 are top plan views of the device in open position andwith different ones of the sheets thereof in open position, FIG. 4showing the covers only in open position, FIG. 5 showing a single one ofthe transparencies in reading position, and FIG. 6 showing two of thetransparencies held rigidly in registration and reading position;

FIG. 7 is a top plan view of a second preferred embodiment of theinvention folding overlay assembly in open position;

FIG. 8 is an edge elevational view of the FIG. 7 assembly on an enlargedscale and prior to lamination of the components; and

FIG. 9 is an exploded view in perspective of the components and showingboth halves of the one-piece transparency imprinted with intelligence.

Referring initially and more particularly to FIG. 1, there is shown onillustrative embodiment of the invention device designated generally 10.This device includes a stiff unitary cover having a central section 11and two covers 12, 13 hinged to its opposite lateral edges along thedouble hinged sections 14, 15. Hinge section 15 is provided with anysuitable binder means for sheet material, as for example, a ring binder17 having any known means for opening the rings thereof for thereception and substitution of sheets of intelligence.

It will be understood that binder means 17 may be associated with eitherof the double hinges 14 and 15, it being immaterial or a matter ofpersonal choice whether the binding is on one or the other side of thecenter plaque. Associated with the cover remote from the binder aresuitable registration means, such as the posts or bosses 19, 19. Theseproject upwardly from the interior surfaces of the binder and areaccurately positioned to extend into openings or notches formed in eachof the transparencies when unfolded and coperating therewith in a mannerto be described more fully below to hold these sheets in accurateregistry with one another and With guide reference means while beinginterpreted.

Desirably the inner surface of cover 12 is Provided with suitable meansfor use in interpreting the information on the transparencies. Typicallyand representative of such assisting devices is the grid work 20comprising equally spaced sets of vertical and horizontal lines.However, it will be understood that the grid work is merelyrepresentative of many graphical interpretation aid devices. For exampleif the device were being used to show the internal construction of anengine with different parts in position relative to the main housing,then the grid work might well comprise a vertical cross-section showingthe engine housing with all or some parts removed. In this case thedifferent transparencies would show different ones of them missingcomponents of this engine and these could then be assembled into theengine body by superimposition of a selected showing upon thecrosssection view of the engine housing.

A typical unitary transparency sheet 25 is best shown in FIG. 3. Onelateral margin, as the left-hand margin is sufficiently wide for abinding or mounting purpose and is here illustrated as provided with arow of holes 26 fitting loosely over rings 17 of the binder. If theoverlay assembly is to be bound with other sheets, perforations 26 maybe omitted and the mounting edge stitched, bonded or otherwise securedto the other overlays. The sheet includes an inner or larger half 27 andan outer or smaller half 28 connected by a hinge line 29 offset slightlyto one side of the transverse center and parallel to the lateral edges.Sheet 25 is formed in one piece of any suitable flexible transparentmaterial of which there are various suitable types readily available onthe open market, particularly among the transparent plasticcompositions. Desirably the material should be smooth and have asufficiently high durometer to form a hinge 29 having a long servicelife. A particular tough and durable material meeting the rigorousrequirements of text book and encyclopedia applications is provided bypolyethylene terephthalate resin available commercially under the tradename of Mylar from E. I. du Pont de Nemours Co. This material may beused in thicknesses of less than 1 to several mils. It is readily foldedto form a permanent hinge line capable of being folded and unfoldedrepatedly without fatigue or failure. This material is readily laminatedor coated with a stiffening layer to discourage the formation ofadditional hinge lines and to facilitate rapid and precise hinging alongthe original hinge axis and to counteract memory characteristics of thetransparent plastic material.

According to one technique, sheets 25 are coated on their upper facewith an opaque or pigmented layer 30 covering substantially all oflarger half 27 and preferably the marginal edges of smaller half 28. Anysuitable coating material may be employed of a type printable with acontrasting color and having a thickness effective to stiffen thetransparency 25 to provide desirable differential stiffness between theuncoated hinge line and the coated or layered material to either sidethereof. In other Words a narrow strip or line 31 bridging hinge 29 ispreferably left uncoated to facilitate the hinging action. Coating 30 onhalf 27 is usually accurately imprinted with the same reference guide asis applied to the surface cover member 12. Thus by way of illustration,half 27 is here shown as provided with a grid 20' identical with grid 20on cover 12. This is so positioned as to directly underlie thetransparent area 33 of half 28 when the sheet is in its normal foldedposition illustrated in FIG.

4. One surface of the transparent area 33 and preferably the rear facethereof is imprinted with any suitable information as for example agrowth line 34. This information is imprinted in such manner as to readgenerally from left to right when folded either against the referencematerial 20' imprinted on the first half of each sheet or againstreference guide 20 imprinted on the interior of cover 12. For thisreason when the transparency is unfolded in the position shown in FIG.3, the information is reversed because this it not the intended positionof use.

To assure proper registration of the information with the referenceguide when unfolded, each of the sheets is preferably provided with oneor more openings at a suitable location for engagement over fixed postsor bosses such as bosses 19, 19. As herein shown these registrationopenings are shown at 36 and are generally V-shaped. Each openingpreferably includes a keyhole portion 37 at its apex to avoid placingundue strain on hinge 29 during handling of the transparencies. Circularportions 37 avoid concentration of the stress directly along the hingeaxis and premature failure of the hinge from this cause.

Although the registration openings are shown at the opposite ends of thehinge line, it will be understood that they may be located elsewhere, asfor example, along the right-hand margin of half 28 when in its openposition as shown in FIG. 3. In this case the registration post would belocated along the left-hand margin of open cover 12. Of importance isthe fact that the registration openings and the cooperating boss orbosses are so positioned with respect to rings 17 as to hold the sheetsaccurately in a predetermined position with the intelligence ontransparency 33 in registration with the reference guide such as gridwork 20.

To make use of the device covers are unfolded and the transparencies areoverturned against cover 13 as shown in FIG. 4. Assuming that the userwishes to compare intelligence on the top sheet with that on the fifthsheet, he unfolds the top sheet and places notches 36 over bosses 19 sothat growth line 34 is in accurate registry with the underlying grid 20.The next three transparencies are then turned over against the centerplaque 11 of the cover unit without being unfolded and superimposed onunfolded sheet No. 1 and over the registration posts 19 in the samemanner as described for that sheet. This brings the particular graphicaldisplay 38 on that sheet into registry with grid 20 and enables the userto compare the one set of information with the other in a manner madeclear by FIG. 6. As will be appreciated, selected additional sheets canbe unfolded against sheets 1 and 5 if the user so desires.

If the user is only interested in the information contained on a singletransparency, such information can always be studied against its ownreference guide without unfolding the-transparency because the referenceguide is always present in accurately registered relation to theinformation on its associated transparency.

If the user wants to make comparison between information contained ontransparencies present in the other sets thereof he need but replace theset then present in binder 17 with a selected new set of transparencies.

Referring now to FIGS. 7 and 8 there is shown a second illustrativeembodiment of the invention comprising a laminated overlay assemblydesignated generally This assembly comprises a first or main body sheetand an identical size second sheet 41 superimposed and laminated to oneanother by a large area layer of suitable bonding material 42 and asecond relatively narrow strip 43 of the same bonding material. Theflexible sheets or films 40, 41 are of suitable transparent material, aspolyethylene terephthalate, of 1 mil or greater in thickness having awidth corresponding to the maximum length of the rectangular overlayassemblies 25'. Strip film material of this character can be readilyassembled from supply rolls of the continuous strip material arranged tobe fed into superimposed relation against the opposite surfaces of twoparallel layers of pigmented bonding agent 42, 43 and held pressedtogether while the agent takes a set. Initially both strips oftransparent material 40, 41 are in one piece but during the laminatingprocedure just referred to, it is desirable to slit the lower strip orsheet 41 as indicated at 45 directly opposite and coincident with thehinge line 29 in top sheet 40. In FIG. 8 slit 45 is shown as a gap butit will be understood that, preferably, the edges of the slit are indirect supporting abutment with one another when assembly 25 is openedto lie in a common plane as in indicated in FIG. 8. it will therefore berecognized that an attempt to fold the outer half 28 of the overlay in aclockwise direction about hinge 29', as viewed in FIG. 8, will beresisted by the abutting edges of slit 45 in lower sheet 41.Contrarywise, if the outer half 28 is folded upwardly counterclockwisetoward half 27' then slit 45 readily opens and the overlay hinges easilyand readily about hinge line 29. The transparent central area of sheet28 is imprinted with intelligence, such as the graph line 34', and thisis readily studied and interpreted in the folded condition of theoverlay against the guide reference imprinted on the larger inner half27' such as the grid 20'.

It will be appreciated from the foregoing description of FIGS. 7 and 8that this embodiment of the invention provides an overlay assembly 25 ofuniform thickness throughout its entire area and is readily fabricatedfrom the strips of very thin, tough, transparent material laminatedtogether in the manner described to provide added stiffness as well asopaqueness in selected areas. Both halves of the overlay can beimprinted with intelligence simultaneously thereby assuring highlyprecise relative positioning of the printing on both the larger innerhalf 27 and the smaller outer half 28'. The second sheet 41 of theoverlay stiffens and re-inforces the main body film 40 and,additionally, the abutting edges of the slit 45 formed in thereinforcing sheet adds very substantially to the stiffening and flatnessof the assembly when in open position, it being self-apparent that theabutting edges resist refolding the overlay in the wrong direction.

From the foregoing description of FIGS. 7 and 8 it will be recognizedthat substantially the full advantages of this two layer laminate can beenjoyed using a strengthening sheet of either transparent or opaquematerial having a size corresponding to that of the bonding agent layer42 in FIG. 8. In other words, the stiffening strip, of paper, pigmentedcoating or the like, is coextensive in size with the larger half 27' ofthe overlay plus the width of the narrow strip of adhesive to the rightof hinge line 29. In this arrangement the portion of the outer half 28-to the right of the right-hand margin of adhesive 42 is omitted.However, the strip of reinforcing material to either side of hinge line29 provides the desired stiffening and memory countering action forhinge line 29 and safeguards against the formation of additional hingelines close to or crossing the original hinge line 29.

It will also be appreciated from the foregoing that if the stiffeningsheet just described in the preceding paragraph is opaque then either apigmented or a non-pigmented or transparent adhesive may be used as thelaminating agent. It will also be understood that the mounting orbinding edge 46 of assembly 25 may be provided with binder perforations26 for use in a ring binder or this edge may be stitched, bonded orotherwise bound to other similar assemblies or to sheets of printedmaterial in accordance with customary bookbinding practice. In thisevent a group of assemblies 25' might be bound into the book in closeproximity to one another in order that any selected one or more of thesmaller halves of the transparencies can be folded outwardly intosuperimposed relation so that the intelligence thereon can beconveniently brought into registry for study and comparison.

It will also be understood that the stiffening lamination or coatinglayer may be confined to either side of hinge line 29' or to a stripalong either side. When using an opaque strip to stiffen the hinge line,a very narrow gap coinciding with the hinge axis is preferably leftuncoated or otherwise provided to avoid bridging the gap with thestiffening layer.

While the particular graphic display assembly herein shown and disclosedin detail is fully capable of attaining the objects and providing theadvantages hereinbefore stated, it is to be understood that it is merelyillustrative of the presently preferred embodiment of the invention.

I claim:

1. A folding graphic overlay comprising a unitary onepiece sheet offlexible transparent film material having a free edge and a parallelbinding edge adapted to be secured to the binding edges of a bookcontaining other flexible sheet material, said sheet having aknife-edge-like hinge line offset slightly from the centerline thereofand parallel to said free edge thereby providing a smaller half and alarger half disposed one on either side of said hinge line, said largerhalf having a second layer laminated thereto generally coextensive insize with the major area of said larger half and including an edgeimmediately contiguous to and substantially coinciding with said hingeline and effective to stiffen said larger half adjacent said hinge lineto facilitate the repeated refolding of said halves along the same hingeline between a first position wherein said smaller half lies flushagainst said larger half and a second position wherein said halves areunfolded to lie flat in a common plane, and said smaller half beinggenerally transparent and imprinted with intelligence which is readableonly when said halves are unfolded.

2. A folding overlay as defined in claim 1 characterized in that saidone-piece sheet of flexible transparent material comprises polyethyleneterephthalate film.

3. A folding overlay as defined in claim 1 characterized in that oneface of said second layer is imprinted with guide reference indiciaregistrable with the intelligence imprinted on said smaller half.

4. A folding overlay as defined in claim 1 characterized in that saidsecond layer comprises a sheet of opaque paper bonded to said largerhalf.

5. A folding overlay as defined in claim 1 character ized in that saidsmaller half of said transparent sheet includes a stiffening layerapplied at least along the edge thereof contiguous to said hinge lineand cooperating with the adjacent portion of said second layer tofacilitate the repeated hinging of said transparent sheet along saidhinge line.

6. A folding overlay as defined in claim 1 characterized in that saidsecond layer comprises an opaque imprintable layer on the exteriorthereof.

7. A folding overlay as defined in claim 1 characterized in that saidsecond layer is opaque and adherent to said larger half of saidtransparent sheet.

8. A folding overlay as defined in claim 1 characterized in that saidsecond layer is laminated to the larger half of said transparent sheetwith a pigmented bonding agent.

9. A folding overlay comprising a unitary one-piece sheet of flexibletransparent material having a free edge and a parallel binding edgeadapted to be secured to the binding edges of other flexible sheetmaterial, said sheet having a hinge line offset slightly from thecenterline thereof and parallel to said free edge thereby providing asmaller half and a larger half disposed one on either side of said hingeline, said larger half having a second layer laminated thereto generallycoextensive in size with the major area of said larger half andincluding an edge substantially coinciding with said hinge line andeffective to stiffen said larger half adjacent said hinge line tofacilitate the repeated refolding of said halves along the same hingeline, the smaller half of said transparent sheet includes an adherentframe-forming layer along the perimeter thereof effective to stiffen thesame with one outer edge thereof terminating closely parallel to saidhinge line and cooperating with the adjacent edge of said second layerof said larger half to facilitate folding said sheet accurately alongsaid hinge line, and said smaller half being generally transparent andimprinted 'with intelligence.

10. A folding overlay comprising a unitary one-piece rectangular firstsheet of film-like transparent material having a hinge line extendingtransversely thereof and offset slightly from the transverse centerlinethereof and dividing said sheet into a larger and a smaller half withthe free edge of the larger half being adapted for binding between thebound edges of other sheet material, a second sheet laminated to saidlarger half effective to stiffen the latter, stiffening sheet materiallaminated to said smaller half with one edge thereof substantiallyabutting the adjacent edge of said sheet along and immediatelycontiguous to said hinge line when said larger and smaller halves lieopen in a common plane, said laminated portions serving to stiffen saidtransparent sheet adjacent said hinge line and facilitating folding saidsmaller half in a direction to bring the exposed surfaces of saidtransparent sheet together and to open the adjacent edges of saidstiffened sheets away from one another.

11. A folding overlay as defined in claim 10 characterized in that saidstiffening sheet laminated to said larger half is rendered opaque bypigmentation.

12. A folding overlay as defined in claim 10 characterized in that saidstiffening sheet laminated to said larger half is bonded to said largerhalf by pigmented bonding agent.

13. A folding overlay as defined in claim 10 characterized in that saidone-piece transparent sheet comprises a dimensionally stable film ofpolyethylene terephthalate.

14. A folding overlay as defined in claim 10 characterized in that saidsecond sheet is coextensive in size with said first sheet and laminatedtogether at least along either lateral side of said hinge line and alongeach transverse end of said rectangular assembly.

15. A folding overlay as defined in claim 10 characterized in that alllaminated surfaces of said first and second sheets are opaque, and inthat the remainder of the smaller half of said first sheet istransparent, and one of the non-laminated portions of said first andsecond transparent sheets being imprinted with intelligence.

16. A device for facilitating comparison of information present on twoor more transparencies in close superimposition, said device comprisinga binder having means for holding a series of transparencies hingedthereto, a plurality of single-piece sheet plastic transparencies heldassembled within said binder each having first and second parts made ofthe same material folded along a transverse hinge line and havingcooperating indicia on the unbound end half of each sheet preciselylocated relative to the associated hinge line and to indicia on other ofsaid transparencies thereby to assure accurate registry of indicia oftwo or more of said transparencies when unfolded from the bound edgethereof to lie against one another in superimposed relation, said secondpart having information thereon and being normally folded compactlyagainst said first part, said binder including a cover having first andsecond parts adapted to be unfolded aloug an axis closely adjacent thehinge between the first and second parts of said transparencies, two ormore of said transparencies selected at random being unfoldable to bringtheir second parts into surface contact with one another against theunfolded second part of said cover, and registration means on said coverclosely adjacent the opposite ends of the hinge between the parts ofsaid transparencies positioned to register with cutouts in saidtransparencies when the latter are unfolded and cooperating therewith tohold the same in predetermined registry for accurate comparison of theinformation thereon.

17. A device as defined in claim 16 characterized in that said firstpart of said transparencies has an opaque coating and in that saidsecond part has an opaque border extending along the rim portionsthereof.

18. A device as defined in claim 16 characterized in that said binderincludes a plurality of rings receivable loosely in a row of openingsalong one lateral edge of the second part of said transparencies.

19. A device as defined in claim 16 characterized in that the rearsurface of the first part and the border portion of the second part ofsaid transparencies when opened are coated with an opaque coating, thecentral portion of said second part being uncoated and imprinted Withinformation readable through the transparency when said second part isunfolded and laid flat against the unfolded second part of said cover.

20. A device for comparing graphically displayed material imprinted onflexible transparent sheet material, said device comprising a unitarystiff cover assembly made in three principal parts including a centralplaque and first and second cover plaques hinged to its opposite lateraledges, looseleaf binder means extending along the hinge between saidcentral and second plaque, a plurality of sheets each comprising asingle plaque of homogenous transparent plastic material held looselybut removably assembled in said looseleaf binder means, each of saidsheets including inner and outer integral halves hinged together along afold axis formed in said transparent plastic material and parallel tobut remote from said binder means and the two halves being normallyfolded together, the inner of said halves being coated with a film ofopaque material, the outer of said halves having information imprintedon one face thereof and being unfoldable to lie flat against the innerface of said first cover plaque in the open position of the latter, andregistration means projecting upwardly from the inner face of said opencover adjacent the hinge axis between the tWo halves of said sheets oftransparent plastic and receivable in an opening in unfolded ones ofsaid sheets and cooperating therewith to hold a plurality of theextended halves of said sheets accurately registered in pre-determinedopen positions supported against the inner face of said first coverplaque so that information on each of the superimposed transparenciescan be compared.

21. A device as defined in claim 20 characterized in that saidregistration means includes a pair of openings adjacent the upper andlower margins of each of said sheets, a pair of complementally shapedposts secured to said stiif cover and projecting upwardly from theinterior surface of said cover in position to extend into said openingsto hold the sheets in predetermined position when engaged over saidposts.

22. A unitary one-piece sheet of flexible transparent plastic materialfolded over against itself along an integral hinge line offset slightlyfrom the centerline of said sheet to provide a mounting strip along theedge of the larger half parallel to and remote from said hinge, saidlarger half being covered with a coating of opaque material imprintedwith reference guide means on its upper face, and the smaller of saidhalves being imprinted with intelligence in accurate registry with saidreference guide means when said smaller half is folded over on top ofsaid larger half.

23. A unitary sheet of material as defined in claim 22 characterized inthat said reference guide means is imprinted on a coating of opaquematerial covering said larger half of the transparent material, and aborder of opaque material surrounding the rim of said smaller half.

24. A unitary sheet of material as defined in claim 22 characterized inthe provision of keyhole openings in said sheet extending toward oneanother from the opposite ends of said hinge.

25. A folding overlay comprising a unitary one-piece flexibletransparent material having a free edge and a binding along the oppositelateral edge thereof adapted to be secured to the binding edges of otherflexible sheet material, said sheet having a hinge line thereacrossbetween said binding edge and said free edge and parallel thereto, asecond sheet of flexible material laminated to said sheet of transparentmaterial and including a slit extending from edge to edge thereof andsuperimposed directly on said hinge line, the edges of said slit beingin direct abutting relation to one another when said hinge is fully openwith said laminate lying substantially in the same plane and therebyeffective to resist folding said laminate except in a direction to opensaid slit edges away from one another.

References Cited UNITED STATES PATENTS 2,155,924 4/1939 Barrett et al.35-53 2,262,796 11/ 1941 Cavalero 281-29 2,309,244 1/1943 Fey 281-382,411,368 11/1946 Dow 281-29UX 2,793,442 5/1957 Ozga 40-158X 3,069,74612/1962 Scharf 161-6 3,091,046 5/ 1963 Engelstein 40102 3,320,225 5/1967 Bradbury 281-37UX FOREIGN PATENTS 16,039 1915 Great Britain 35-40421,347 12/ 1934 Great Britain 35-26 989,598 4/ 1965 Great Britain 40360HARLAND S. SKOGQUIST, Primary Examiner US. Cl. X.R. 35-50; 281-38

